1. Field
The embodiment(s) herein relate to a communication control apparatus and method thereof.
2. Description of the Related Art
A RAID device (Redundant Arrays of Inexpensive Disks) includes a plurality of communication paths even for the same HDD so that reading/writing of data, etc., to and from the HDD can be maintained even if a failure occurs in the device. This will be specifically described with reference to FIG. 14. FIG. 14 is a diagram for explaining a RAID device.
As illustrated in FIG. 14, there are a plurality of route switches and switches between a controller and HDD in a RAID device 10. The route switches and the switches establish a plurality of communication paths for communications between the controller and the HDD.
The communication paths include predetermined communication paths (main system: solid lines of FIG. 14) used in normal operation and auxiliary communication paths (redundant system: dotted lines of FIG. 14) serving as a backup for continuing reading/writing of data to and from the HDD when a failure occurs in the main system.
Therefore, even if a failure occurs in the main system of the RAID device 10, switching the communication paths from the main system to the redundant system based on an instruction from the controller allows continuation of data reading/writing, etc., to and from the HDD in the RAID device 10, and the operation of the RAID device 10 can be maintained.
However, when there is no failure, only the main system is used, and the redundant system is not used in some cases. In that case, the power of the switches and the HDD of the redundant system are on, and there is unnecessary power consumption in the redundant system.
Thus, to reduce the power consumption of the redundant system, there is a technique for turning on the power when the HDD of the redundant system is used and a technique for turning on/off the power of the switches of the redundant system according to the access frequency to the HDD. Referenced documents are Japanese Laid-Open Patent Publication No. 2004-326244 and 2007-141047.